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-rw-r--r--drivers/md/persistent-data/dm-space-map-disk.c3
-rw-r--r--drivers/md/persistent-data/dm-space-map-metadata.c127
-rw-r--r--drivers/md/persistent-data/dm-space-map.h23
3 files changed, 140 insertions, 13 deletions
diff --git a/drivers/md/persistent-data/dm-space-map-disk.c b/drivers/md/persistent-data/dm-space-map-disk.c
index f6d29e614ab..e735a6d5a79 100644
--- a/drivers/md/persistent-data/dm-space-map-disk.c
+++ b/drivers/md/persistent-data/dm-space-map-disk.c
@@ -248,7 +248,8 @@ static struct dm_space_map ops = {
.new_block = sm_disk_new_block,
.commit = sm_disk_commit,
.root_size = sm_disk_root_size,
- .copy_root = sm_disk_copy_root
+ .copy_root = sm_disk_copy_root,
+ .register_threshold_callback = NULL
};
struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index 906cf3df71a..1c959684cae 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -17,6 +17,55 @@
/*----------------------------------------------------------------*/
/*
+ * An edge triggered threshold.
+ */
+struct threshold {
+ bool threshold_set;
+ bool value_set;
+ dm_block_t threshold;
+ dm_block_t current_value;
+ dm_sm_threshold_fn fn;
+ void *context;
+};
+
+static void threshold_init(struct threshold *t)
+{
+ t->threshold_set = false;
+ t->value_set = false;
+}
+
+static void set_threshold(struct threshold *t, dm_block_t value,
+ dm_sm_threshold_fn fn, void *context)
+{
+ t->threshold_set = true;
+ t->threshold = value;
+ t->fn = fn;
+ t->context = context;
+}
+
+static bool below_threshold(struct threshold *t, dm_block_t value)
+{
+ return t->threshold_set && value <= t->threshold;
+}
+
+static bool threshold_already_triggered(struct threshold *t)
+{
+ return t->value_set && below_threshold(t, t->current_value);
+}
+
+static void check_threshold(struct threshold *t, dm_block_t value)
+{
+ if (below_threshold(t, value) &&
+ !threshold_already_triggered(t))
+ t->fn(t->context);
+
+ t->value_set = true;
+ t->current_value = value;
+}
+
+/*----------------------------------------------------------------*/
+
+/*
* Space map interface.
*
* The low level disk format is written using the standard btree and
@@ -54,6 +103,8 @@ struct sm_metadata {
unsigned allocated_this_transaction;
unsigned nr_uncommitted;
struct block_op uncommitted[MAX_RECURSIVE_ALLOCATIONS];
+
+ struct threshold threshold;
};
static int add_bop(struct sm_metadata *smm, enum block_op_type type, dm_block_t b)
@@ -144,12 +195,6 @@ static void sm_metadata_destroy(struct dm_space_map *sm)
kfree(smm);
}
-static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
-{
- DMERR("doesn't support extend");
- return -EINVAL;
-}
-
static int sm_metadata_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
@@ -335,9 +380,19 @@ static int sm_metadata_new_block_(struct dm_space_map *sm, dm_block_t *b)
static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
{
+ dm_block_t count;
+ struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
+
int r = sm_metadata_new_block_(sm, b);
if (r)
DMERR("unable to allocate new metadata block");
+
+ r = sm_metadata_get_nr_free(sm, &count);
+ if (r)
+ DMERR("couldn't get free block count");
+
+ check_threshold(&smm->threshold, count);
+
return r;
}
@@ -357,6 +412,18 @@ static int sm_metadata_commit(struct dm_space_map *sm)
return 0;
}
+static int sm_metadata_register_threshold_callback(struct dm_space_map *sm,
+ dm_block_t threshold,
+ dm_sm_threshold_fn fn,
+ void *context)
+{
+ struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
+
+ set_threshold(&smm->threshold, threshold, fn, context);
+
+ return 0;
+}
+
static int sm_metadata_root_size(struct dm_space_map *sm, size_t *result)
{
*result = sizeof(struct disk_sm_root);
@@ -382,6 +449,8 @@ static int sm_metadata_copy_root(struct dm_space_map *sm, void *where_le, size_t
return 0;
}
+static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks);
+
static struct dm_space_map ops = {
.destroy = sm_metadata_destroy,
.extend = sm_metadata_extend,
@@ -395,7 +464,8 @@ static struct dm_space_map ops = {
.new_block = sm_metadata_new_block,
.commit = sm_metadata_commit,
.root_size = sm_metadata_root_size,
- .copy_root = sm_metadata_copy_root
+ .copy_root = sm_metadata_copy_root,
+ .register_threshold_callback = sm_metadata_register_threshold_callback
};
/*----------------------------------------------------------------*/
@@ -410,7 +480,7 @@ static void sm_bootstrap_destroy(struct dm_space_map *sm)
static int sm_bootstrap_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
- DMERR("boostrap doesn't support extend");
+ DMERR("bootstrap doesn't support extend");
return -EINVAL;
}
@@ -450,7 +520,7 @@ static int sm_bootstrap_count_is_more_than_one(struct dm_space_map *sm,
static int sm_bootstrap_set_count(struct dm_space_map *sm, dm_block_t b,
uint32_t count)
{
- DMERR("boostrap doesn't support set_count");
+ DMERR("bootstrap doesn't support set_count");
return -EINVAL;
}
@@ -491,7 +561,7 @@ static int sm_bootstrap_commit(struct dm_space_map *sm)
static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
{
- DMERR("boostrap doesn't support root_size");
+ DMERR("bootstrap doesn't support root_size");
return -EINVAL;
}
@@ -499,7 +569,7 @@ static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
static int sm_bootstrap_copy_root(struct dm_space_map *sm, void *where,
size_t max)
{
- DMERR("boostrap doesn't support copy_root");
+ DMERR("bootstrap doesn't support copy_root");
return -EINVAL;
}
@@ -517,11 +587,42 @@ static struct dm_space_map bootstrap_ops = {
.new_block = sm_bootstrap_new_block,
.commit = sm_bootstrap_commit,
.root_size = sm_bootstrap_root_size,
- .copy_root = sm_bootstrap_copy_root
+ .copy_root = sm_bootstrap_copy_root,
+ .register_threshold_callback = NULL
};
/*----------------------------------------------------------------*/
+static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
+{
+ int r, i;
+ enum allocation_event ev;
+ struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
+ dm_block_t old_len = smm->ll.nr_blocks;
+
+ /*
+ * Flick into a mode where all blocks get allocated in the new area.
+ */
+ smm->begin = old_len;
+ memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
+
+ /*
+ * Extend.
+ */
+ r = sm_ll_extend(&smm->ll, extra_blocks);
+
+ /*
+ * Switch back to normal behaviour.
+ */
+ memcpy(&smm->sm, &ops, sizeof(smm->sm));
+ for (i = old_len; !r && i < smm->begin; i++)
+ r = sm_ll_inc(&smm->ll, i, &ev);
+
+ return r;
+}
+
+/*----------------------------------------------------------------*/
+
struct dm_space_map *dm_sm_metadata_init(void)
{
struct sm_metadata *smm;
@@ -549,6 +650,7 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
smm->recursion_count = 0;
smm->allocated_this_transaction = 0;
smm->nr_uncommitted = 0;
+ threshold_init(&smm->threshold);
memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
@@ -590,6 +692,7 @@ int dm_sm_metadata_open(struct dm_space_map *sm,
smm->recursion_count = 0;
smm->allocated_this_transaction = 0;
smm->nr_uncommitted = 0;
+ threshold_init(&smm->threshold);
memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
return 0;
diff --git a/drivers/md/persistent-data/dm-space-map.h b/drivers/md/persistent-data/dm-space-map.h
index 1cbfc6b1638..3e6d1153b7c 100644
--- a/drivers/md/persistent-data/dm-space-map.h
+++ b/drivers/md/persistent-data/dm-space-map.h
@@ -9,6 +9,8 @@
#include "dm-block-manager.h"
+typedef void (*dm_sm_threshold_fn)(void *context);
+
/*
* struct dm_space_map keeps a record of how many times each block in a device
* is referenced. It needs to be fixed on disk as part of the transaction.
@@ -59,6 +61,15 @@ struct dm_space_map {
*/
int (*root_size)(struct dm_space_map *sm, size_t *result);
int (*copy_root)(struct dm_space_map *sm, void *copy_to_here_le, size_t len);
+
+ /*
+ * You can register one threshold callback which is edge-triggered
+ * when the free space in the space map drops below the threshold.
+ */
+ int (*register_threshold_callback)(struct dm_space_map *sm,
+ dm_block_t threshold,
+ dm_sm_threshold_fn fn,
+ void *context);
};
/*----------------------------------------------------------------*/
@@ -131,4 +142,16 @@ static inline int dm_sm_copy_root(struct dm_space_map *sm, void *copy_to_here_le
return sm->copy_root(sm, copy_to_here_le, len);
}
+static inline int dm_sm_register_threshold_callback(struct dm_space_map *sm,
+ dm_block_t threshold,
+ dm_sm_threshold_fn fn,
+ void *context)
+{
+ if (sm->register_threshold_callback)
+ return sm->register_threshold_callback(sm, threshold, fn, context);
+
+ return -EINVAL;
+}
+
+
#endif /* _LINUX_DM_SPACE_MAP_H */